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INJURIOUS INSECTS AND FUNGI. 



[Dec. 1890. 



The caterpillars seem to have many natural enemies, notably 

 some species of flies which lay their eggs in the larvae. 

 Insectivorous I irds, certain beetles, and even swine devour them 

 greedily. These, with climatic causes, are usually sufficient to 

 keep them in check, and the conditions favourable to a large 

 swarm have not been clearly determined. The best method of 

 stopping their ravages would appear to be the interposition of 

 a ditch to bar their progress ; while such measures as spraying 

 a strip of field, towards which they are moving, with Paris 

 green (afterwards destroying ifc to prevent injury to stock), 

 heavily rolling the ground, or distributing slacked lime broad- 

 cast, have also been resorted to with a certain measure of 

 success. 



The insect has been a rare and accidental visitor to this 

 country for many years, while in France and Germany it is not 

 known to be in any way injurious to crops. 



The Woolly Aphis, or American Blight 

 (Schizoneura lanigera). 



1 



2. Winged female, magnified; and line showing natural size. 2. Wingless 

 viviparous female, magnified.* 3. Apple twig, covered by woolly aphides. 



This insect has decidedly increased during the last few years, 

 particularly in orchards and apple plantations where the trees 

 have been unpruned and neglected ; and its action is most 



* Fig. 2 is reproduced, with permission, from Mr. G. B. Buckton'a " British Aphides" 



